Properties of flexible phosphorescence polymer light emitting diodes coated on polyethylenenaphthalate plastic substrates.

Flexible phosphorescence polymer light emitting diodes (PhPLEDs) with PEN/ITO/PEDOT:PSS/ PVK:Ir(ppy)3/TPBI/LiF/Al structure were fabricated to investigate the effects of Ir(ppy)3 doping concentrations on the optical and electrical properties of the devices. PVK and Ir(ppy)3 conjugated polymers as host and guest materials in the emission layer were spun coated at various concentrations of Ir(ppy)3 ranging from 2.0 to 8.0 vol%. As the concentration of Ir(ppy)3 increased from 2.0 to 6.0 vol%, the electrical and optical properties of the flexible PhPLEDs were improved clearly. Maximum luminance and current density were obtained for a PhPLED with an Ir(ppy)3 concentration of 6.0 vol%, with 6815 cd/m2 and 393 mA/cm2 at 9 V. The current efficiency tends to increase with the Ir(ppy)3 concentration, because of the formation of the excitons required to emit light.

Prevalence of human papillomavirus and Chlamydia trachomatis infection among women attending cervical cancer screening in the Republic of Korea.

Cervical cancer screening with the conventional Papanicolaou test is recommended for the women aged 30 years and more in Korea. Cervical infection with human papillomavirus (HPV) is the most important cause of cervical cancer and Chlamydia trachomatis (CT) is the most common bacterial sexually transmitted infection and may also be associated with risk of cervical cancer. A cross-sectional study of women attending the National Cervical Cancer Screening Program in Busan and Suwon was carried out. Exfoliated cervical cells were collected, and questionnaires were administered to 4595 women. High-risk HPV types and CT were tested by Hybrid Capture 2 (HC2). HPV genotyping of 355 high-risk HPV-positive women at HC2 was performed using linear array. Age-standardized prevalence of high-risk HPV types and CT was 10.4% (95% confidence interval: 9.5-11.3) and 4.3% (95% confidence interval: 3.7-4.8). That 68.5% of women were high-risk HPV-positive at HC2 was confirmed by Linear Array whereas 17.5% seemed to be infected with only low-risk HPV types, not normally detected by HC2. Korean women showed a relatively high prevalence of high-risk HPV and a rather low prevalence of CT. As in cancer-free women in other Asian populations, HPV 52, 58, and 39 were detected more frequently than HPV 16. Cross-reaction of HC2 with low-risk HPV types is of some concern, were the test to be used in primary screening.